is it supposta have both nUI6 unitframes and the default blizzard unitframes?

Take a closer look at Scott's post & you'll find your answer there:

Originally Posted by spiel2001

In addition, this first alpha does not contain casting bars or auras (buffs/debuffs) on purpose as both are graphics rendering intensive. With that in mind, the default Blizz player and target unit frames are enabled along with the default casting bar and aura displays.